Transmission control system and mechanism



Jan. 7, 1941.

TRANSMISSION CONTROL SYSTEM AND Filed Aug. 1',- l39 F. LINSLEY ETIAL MECHANISM 5 Sheets-Sheet 1 DOUGLAJ f. LIA/915V.

Haze r L, Chum/'01., e/e.

Jan; 7, 1941.

D. F. LINSLEY ETALY 2,227,658

TRANSMISSION CONTROL SYSTEM AND MECHANISM Filed Aug. 7, 1939 s Sheets-Sheet 2 1941- D. LINSLEY ETAL 2,227,558

TRANSMISSION CONTROL SYSTEM AND MECHANISM Filed Aug. 7, 1939 5 Sheets-Sheet 3 DauaL/m' fi AINOLEV. bheer LJCWJ/MLM, c/e. 41-35871 5 H ILGGAI.

Jan. 7, 1941. D. F. LINSLEY ElxAL 2,227,658

TRANSMISS ION CONTROL SYSTEM AND MECHANISM I Filed Aug. '7, 1939 5' Sheets-Sheet 4 fil E1 Z :1 5 DOUGLAJ' f 1/4/6457 Hmeer' L. Cum-H04, c/e.

Jan. 7, 1941 F. LINSLEY EI'AL 2,227,658

TRANSMISSION CONTROL SYSTEM AND MECHANISM Filed Aug. 7, lse 5 Sheets-Sheet 5 00061-4 a li Luvs-4.5).

reversing valve is provided controlled by the Patented Jan. 7,1941

PATENT OFFICE TRANSMISSION common srs'rnu AND MECHANISM Douglas F. Linsley and Harry L. Chisholm, Jr.,' Buflalo, N. Y., and Albert E. Wilson, Euclid, Ohio; said Linsley and said Chisholm assignors to Houde Engineering Corporation, Buffalo,

. 'N. Y., a corporation of New York, and said Wilson assignor to The White Motor 00.; Cleveland, Ohio, a corporation of Ohio Application August 7;

, 5 Claims.

This invention relates to transmission control in automotive vehicles and particularly to that type of control in which selection for desired transmission speed is effected by a hand lever 5 preferably located adjacent'to the steering wheel and the shifting of the selected transmission gearing is effected by power means in which the power medium is preferably the vacuum gener-v from the main valve. This copending applica-' tion control system. also embodies an auxiliary valve for' controlling the application of vacuum to a diaphragm structure for operating the cutof! valve and with the auxiliary valve operable in synchronism with the speed selection means in tioi lever at the steering wheel. In addition, a

valve is closed.

In this application the drawings are the same as those in the copending' application except for a; change in the connection of the auxiliary valve vacuum supply line relative to the main or clutch controlled valve. In the impending application referred to. the main valve controls the supply of vacuum to the auxiliary valve, while in the arrangement in this application the auxiliary valve receives its vacuum supply directly from the vacuum source, independent of the main valve. The specification in this application is therefore substantially the same as that of the copending application except for the difference in operation connection for the auxiliary valve.

The various features of the invention are incorporated in the structure shown 'on the drawings, in which drawings.

Figure 1 is a diagrammatic layout of our imthe transmission housing operable by the selecshifted back to normal position when the relay 2 and effect caused by the change in the vacuum 1939, Serial No. 288.806

proved control showing the various cooperating structures and the interconnections;

Figure 2' is a plan view showing a transmission housing with the cover removed and showing also the power cylinder, the relay and reversing valve 5 structure, and the auxiliary valve structure;

Figure 3 is a diametral section through the cutof! and reversing valve structure and part of the power cylinder; I,

' Figure 4 isa view on plane IVIV Figure 3; 10

Figure 5 is an enlarged plan view of the auxiliary valve structure with the valve housing in diametral section;

Figure 6 is a section on plane VI-VI Figure 5; Figure 7 is a vertical sectional view of the clutch operated valve;

Figure 8 is a section on plane VIII-VIII Fig-- ure '7;

Figure 9 is a diagram showing signal circuit arrangement for indicating various conditions of operation of the control system.

Referring to the layout-shown on'Figure 1, T represents the transmission housing within which are the gear selection and gear shifting assemblies. Pindicates the power cylinder for effecting "the shifting operation. R indicates the cutoff and reversing valve structure for controlling the application of the power medium, in this casethe vacuum generated by the vehicle engine, to the power cylinder P. V indicates the valve structure controlled by operation of the clutch pedal C for controlling the supply of vacuum. M indicates a control lever adjacent the steering. wheel of the vehicle for selecting the desired transmission speed ratio. S indicates a selector rack cooperating with means within the transmission casing T for setting the selection assembly for the desired speed ratio; U represents the auxiliary valve for control of the application of' vacuum or, atmosphere to the cut-oil? valve in the structure R. the valve U and the selector rack S being coniointly. actuated upon manipulation of the selection lever M. .w represents a reservoir for vacuum power supply.

'The'gear selection and shifting assembly with- 45 in the transmission housing T may be of any suitable type. As shown on Figure 2, it is substantially the same as that disclosed in the copending application of Peo, Chisholm and Linsley, Serial No. 21,5,7'76, fi1ed June 25, 1938. Briefly describing this selection and shift assembly, it comprises the shifter rods Id and II carryin the heads I! and II from which extend the shifter ,forks (not shown). The selector elements I l and II are mounted on a tubular shaft I 8 iournaled '55 at one end on a fixed pin l1 and at its other end having the pin l8 secured thereto and extending therefrom. As fully described in the copending application of Peo, Chisholm and Linsley referred to, the selector elements are rotatable on the tube l8 for selection of a desired speed 'ratio, and are axially shiftable on the tube for neutralization of the transmission gearing and shift thereof for the selected speed ratio, the selector elements having the selector notches IQ for receiving the coupling plungers 28 housed in the fork heads l2 and I3. The selector element bodies have respectively circumferentially extending channels 2| and 22 for receiving pins 23 and 24 extending from the gear sectors 25 and 28 pivoted on the transmission housing, the sector 28 being engaged by a crankshaft 21 extending laterally from the transmission housing and at its outer end provided with a lever 28 connected with the rod 23 extending from the piston 38 within the power cylinder P. Normally the piston is at the rear end ofthe cylinder and the selector elements are separated as shown on Figure 2, a forward stroke of the piston causing the selector elements to be brought together and the fork heads returned to neutral and a selector notch I3 brought into alignment to receive the corresponding coupling plunger 20, and the rearward stroke of the piston causing the selector elements to be shifted apart and the coupled fork head carried therewith for shift into the selected gear ratio.

For rotational setting of the selector elements for gear selection, the selector rack S meshes a gear sector 3| secured on the pin II which is fastened to the tubular shaft i6. As best shown on Figure 1, the selector rack is connected by a link 32 with one end of a bell crank lever 33 pivoted on a bracket 34 extending from the transmission housing, the other end of the lever being connected by the rod 35 to an arm 38 extending from the lower end of the shaft 31 at the upper end of which is secured the manually operable selection lever M adjacent to the steering wheel. The clutch pedal operable valve V is shown on Figures '7 and 8. ,It comprises a substantially V-shaped body 38 at the apex of which is journaled the shaft 33 from which the valve arm 40 extends, the shaft 33 at its outer end having secured thereto the operating lever 4| which, as shown on Figure 1, is in the path of an adjustable abutment post.42 on an arm 43 extending from the shaft 44 on which the clutch lever C is mounted.

The detachable cover 45 for the valve body provides the valve chamber 45 having the seat 41 whose curvature is centered at theaxis of the shaft 33, the seat being engaged by the valve shoe 48 movable with the arm 43. As shown the end of the arm extends into the recess 43 of the valve shoe, the spring 50 within the arm tending to yieldably hold the valve to its seat as the arm is swung.

The valve body has the tubular extension 38 for accommodating a spring for normally holding the valve arm against a stop 5|. As shown a rod structure 52 extends through the extension from the head thereof to form a seat for the inner end of a compression spring 53 which at its outer end abuts the hook ends 54 of a hairpin frame whose bend receives a pin 55 extending between ears 55 on the valve arm 40, the spring thus yieldingly'holding the valve arm normally against the stop 5|.

The valve shoe has the rectangular port 51 for cooperating with the rectangular ports 58 and 53 in the cap 45 and terminating at the surface 41 along which the valve shoe operates. The port 58 leads to a bore 68 with which a pipe 8| communicates, and the port 53 leads to a bore 62 with which a pipe 63 communicates. As shown on Figure 1, the pipe 8| to the valve V extends from the reservoir W which is connected with the intake manifold 64 of the vehicle engine 65. The pipe 63 extends to the relay and reverse valve structure R.

Referring to Figure '1, the valve body 38 has air inlets 66 so that the interior of the housing is normally subjected to atmospheric pressure, and to guard against dust or dirt entering with the air, the valve body has an enlargement 61 forming a filter chamber for filtering material 68 in advance of the inlet 56.

Inthe normal position of the valve shoe with the arm 40 against the stop 5|, the valve port 51 registers with the vacuum port 58, the heel of the valve shoe partially overlapping the port 53' so that air may flow through the pipe 63 for venting of chambers previously subjected to vacuum. When the valve arm 40 is swung away from its normal position, the valve shoe will shut off the port 53 fromatmosphere and the valve port 51 will span the ports 58 and 53 for delivery of vacuum from the pipe 6| to the pipe 63 and to the various control elements to be operated. As .soon as the valve is returned to its normal setting, these elements will be vented to atmosphere. 0n Figure '1 to the full lines show the valve in normal position and the dotted lines show it in its position for spanning the ports 58 and 59. Referring to Figure 1, the abutment post 42 is so set that upon depression of the clutch pedal C, the arm 4| will not be actuated for valve movement until the clutch has been fully disengaged.

The cut-offend reversing valve structure is best shown on Figures 3 and 4. The structure comprises a body 63 having the outer longitudinal bore 10, and the inner bore 1| concentric with the bore 18 but of somewhat larger diameter. Operable within the bore 10 is the cut-oil valve 12 secured on a stem 13 which extends through the bore 18 and into the bore 1|. Communicating with the bore or valve chamber 10 is the port 14 with which connects the pipe 63 extended from the clutch operatedvalveV. The bore or valve chamber 10 also communicates with a pipe 15 extending therefrom opposite the port 14. The valve 12 has a circumferentially extending port 16 for connecting the pipe 15 with the port 14 when the valve is shifted outwardly from its normal position. At its outer end, the valve body 63 has a flaring extension 11 covered by a cap 18, a diaphragm 19 being interposed between the extension and the cap to form inner and outer chambers 80 and 8|, the stem 13 of the valve 12 beingsecured at its outer end to the diaphragm. A pipe 82 extends from the outer chamber 8| for the application of vacuum or atmosphere in the chamber. A spring 83 nested in the outer end of the valve and abutting the body 63 at its outer end tends to holdthe valve in its normal or inner position with the valve port 16 displaced from the port 14, the valve. chamber 1|! communicating with the inner diaphragm chamber 80 through the passage 84. Upon the application of vacuum in the outer diaphragm chamber 8|, the valve will be shifted outwardly for connection by its port 16 of the pipe 63 with the pipe 15.

The bore 1| forms a chamber for the reversing valve 85, this valve being cylindrical and having the circumferentially extending port 86 intermediate its ends. At one side of the valve cham-'- ber II, the valve body has the enlargement 81 covered by a cap 88 and providing outer and in ner chambers 89 and 90. A port 9| extends through the enlargement to connect the valve chamber II with the passage 92 in the cap 88 which communicates. with the pipe I5 extending from the valve chamber 10 for the cut-off valve. Adjacent to the port 9l, a port 98 connects the chamber 89 with the valve chamber II at the inner side of the valve 85, and a port 94 connects the chamber 90 with the valve port 86 when the valve is in its normal position as shown in Fig- I on Figure 3, a Spring pressed detent ball II8 enure 3.

The valve body 69 is supported by a bracketor wall 95 extending radially from the outer head 96 of the power cylinder P, the valve body being detachably-secured as by means of screws 81. In the outer side of the wall 95 is an arcuate channel 98 communicating at one end with the chamber 90 and at its other end with a passage as through the cylinder head as and to the forward end of the cylinder. The wall 96 has also the passageway I00 therethrough registering at its outer end with the passageway IIII extending through the enlargement 81 and terminating'in the chamber 89, the outer end of the passageway I00 communicating with a pipe I02, this pipe leading to the rear end of the power cylinder behind the piston 30.

Between the wall 95 and the valve chamber II,

-- filtering means (not shown).- Through the rev I08 through its inner end connected with the outer end of the valve chamber II by the port I06 and connected by a port IIO with the valve chamber I0 outside of the valve 12.

When the cut-off and reversing valve ports are in normal position as shown on Figure 3, the stern I3 of the cut-off valve is forced inward by the spring 83 to abut the reversing valve 8 to hold the end of the stem I04 against the wall 85, the reversing valve in this position having its port 86' spanning the ports 9I and 8|. If now vacuum is applied in the outer diaphragm cham: ber 8|, the cut-off valve 12 will be shifted outwardly for connection by its port 18 of the vacuum pipe 63 with the pipe 15 which communicates with the port 9|, and the outer end of the power cylinder will be subjected to vacuum through the chamber 98, the arcuate passageway 98, and the passageway 99, and. the piston will be shifted forwardly in the cylinder for bringing the selector elements I4 and IS in the transmission housing together and to bring the shifter forks to neutral position ready tors; shift of the selected gearing. An important object of our invention'is to provide means, automatically opend of the power cylinder from vacumnand to' connect the inner end of the cylinder with vacuum so that the piston will be pulled back to effect the shifting of the selected transmission gearing. Referring to Figure 3, this valve shifting means is in the form of a plunger assembly comprising a cylindrical shifter bar III which is shiftable in the passageway II2 in the cylinder head 96 to project into the chamber I03 where it is connected by a tie bar II3 with the end of the stem' I04 on the reversing valve 85. The bar has the bore III for a plunger I I5, from which a pin IIB extends out through the inner end of the bar, the spring I I1 within the bore tending to hold the plunger in its outer position. When the parts, are in their normal positions as shown gages in the detent channel 9 in the bar III to resist outward movement thereof. During the final outward movement of the piston in the power cylinder, the piston will first engage with the pin H6 and will force the plunger II 5 inwardly against the resistance of the spring I" and then. when the piston, during its final outward travel, engages the shift bar III ,it will release the bar from the detentball H8, and the spring III will then quickly shift and snap the bar inwardly for-snap shift of the reversing valve 85 into its outer position, indicated by dotted lines in Figure 3. In this outwardly shifted position of the reversing valve, its port 86 will span the port 92 and the port 93 so that the outer end of the cylinder will be subjected' to vacuum through the passageway I M in the valve body 69, the passageway I00 in the wall 95, and then the pipe I02 connecting with the rear end of the cylinder. Thus, after an outward movement of -the piston for neutralizing the gears and connection of; the respective selector elements with the fork head of the selected gear, the piston' itself will set the reversing valve for flow of vacuum for returning the piston to its inner position for shift of the selected 'gear. In order that complete and 'efiective neutralization may be effected before shifting, the shifter bar III is provided with a second channel IISI' to be en-- gaged by the detent ball II8 when the bar has been shifted outwardly it: shifting of the re-;

versing valve. a

A neutralization followed by a shifting by the power cylinder occurs while the outer diaphragm chamber 8| is subjected to vacuum. By means of the auxiliary valve structure U, which will be described in detail later, the diaphragm chamber 8| is vented to atmosphere when the manual selecting lever M (Figure 1) is shifted from one index setting to another, and when the diaphragm is thus released from vacuum, the spring 83 will shift the cut-nif valve I2 back to its normal position, and in such-movement of the valve, its stem I3 will encounter the reversing valve 86 and will shift this valve back to its normal position, the cut-off valve during its movement cutting off the vacuum pipe 63 from the pipe I6. A'

spring I20 is interposed between the reversing valve and the valve body 88 which spring is com-' pressed when the reversing valve is shifted out-' wardly by the engagement of the power cylinder against the efiorts of the spring I20. However, .whenthe spring 83 shifts the cut-off valve 12 audits stem I8 back to the normal position and carries therewith the reversing valve, the detent channel 9' of the shift bar III will be released from the detent ball H8 and then the spring I20 will quickly snap the reversing valveback to its normal position and restore the shift bar III to its inner position ready for the next engagement therewith by the power cylinder piston. When the selection by the manual lever M for succeeding speed is completed, the outer diaphragm chamber 8I- will again be subjected to vacuum and the cut-off valve drawn out for connection of the vacuum pipe 63 with the pipe I5 and the outer end of the cylinder will be subjected to vacuum for outward travel of the piston and engagement of the piston with the shift bar III for setting 'of the reversingvalve for the application of vacuum to the inner end of the cylinder so that neutralization of the gearing is quickly followed by shift of the selected gearing.

When the outer end of the power cylinder is subjected to vacuum, the inner end thereof is open to the atmosphere through the pipe I02 which then communicates through the passageway IM and the port 93 with the inner end of the valve chamber II which is connected with atmosphere through the atmosphere inlet I06. When the inner end of the power cylinder is subjected to vacuum, the outer end thereof is open to the atmosphere by way of the passageway 98, the chamber 90, port 94 and the chamber I03 which has the atmosphere inlet I05. The diaphragm I0 is also always free to move in response to vacuum as the diaphragm chamber 80 is always in communication through the valve stem bore I00 with the outer end of the valve chamber II which has the atmosphere inlet I06.

The auxiliary valve structure U is shown in detail in Figures 5 and 6. It comprises a tubular valve housing I2I supported in a collar I22 which may be secured to a bracket I23 (Figure 2) extending from the transmission housing T, the axis of the valve housing being parallel with that of the selector rack bar S on the transmission housing. Shiftable within the valve housing is the cylindricalauxiliary valve I 24 which at its outer end has an eye I25 receiving the end of an arm I26 rigid with and extending from the inner end of the link 32 which connects the selector rack S with the lever 33 (Figure 1). With this arrangement, the auxiliary valve shifts with and follows the movements of the selector rack S as the manual setting lever M is operated. The purpose of this auxiliary valve is to operate coincidentally with the setting of the speed selector rack S to control the application of vacuum to the diaphragm chamber 8I for opening of the cut-off valve I2, and the application of atmosphere to this diaphragm chamber for c10- sure of the cut-off valve when passing from one selection index position to another. The pipe 82 to the diaphragm chamber 8I communicates with the bore of the valve housing I 2I and through a vacuum port I 21 through atmosphere ports I28 and I29. Referring to Figure l, a pipe I30 communicates with the valve housing I2I through a port I3I, and this pipe is connected to receive vacuum directly from the supply source which position.

between the atmosphere ports I 20 and I29 in I the valve housing is equal to the spacing between the valve ports. The valve housing has two other ports I32 and I33 circumferentially displaced from the ports I 28 and I 29 respectively but in circumferential alignment therewith so as to communicate therewith when the valve I24 is shifted for closure of the port I21 and registration of adjacent valve selection ports with the ports I28 and I29. Referring to Figure 6, the valve housing is cut away to provide a recess I34 connecting the ports I32 and I33, and this recess communicates with an atmosphere inlet I35-provided on the collar I22. In order to assure the entrance of clean air, a filter cup I36 may be applied in the inlet I35 and filled with filter material I31.

As shown on Figure 1, the manual selection lever M is at the N or neutral index position, and the selector rack S is therefore at neutral setting, and the auxiliary valve I24 is likewise in neutral setting as shown on Figure 5. If the engine is operating or there is vacuum in the reservoir W, the diaphragm chamber 8| will be subjected to vacuum through the pipe I30, ports I3! and I2! of the auxiliary valve U, and pipe 1 82, and the cut-ofi valve will be opened so that,

. cylinder and a power ,cycle will result as has already been described; However, as the selector elements I4 and, I5 are at neutral setting, the transmission gearing will remain at neutral and there will be no gear shifting.

If setting by the manual lever M is made to another index position, the valvs I24 will be correspondingly shifted, and during such shift from one index position to another, the ports I21 and I3I on the selector valve will be closed and two of the valve ports will be in registration with the atmosphere ports I28 and I29 to subject the diaphragm chamber ill to atmosphere for release of the cut-01f valve and return thereof to closed When the new index position is reached, this atmosphere path will be closed and the vacuum ports I21 and I3I again put into communication for opening of the cut-oil valve so that when the clutch pedal is depressed for opening of the valve V the power cylinder W111 be subjected to vacuum for a cycle of gear neutralization and shift thereby. For example, 'suppose that low speed drive is desired, the lever M is moved to the low speed index for setting of the selector rack S and the selector elements for that speed, and the auxiliary valve I24 will be correspondingly set for communication of its port L with the ports I21 and I 3I for delivery of vacuum to the diaphragm chamber and opening of the cut-off valve 12. During such setting movement from neutral to low speed, the auxiliary elements and the selector valve will pass through the index setting for third or high speed H and the auxiliary valve will vent the diaphragm chamber to atmosphere during such passage from neutral to low speed, but there will be no operation by the power cylinder until the main valve V is opened, and when the selection setting for low speed has been completed, the clutch may be depressed for opening of the valve V for vacuum supply to the power cylinder and it will then effect neutralization of the transmission gears and shift thereof for low speed transmission.

It will be noted that the ports" I21 and BI are in the form of circumferentially extending slots which are rather narrow but comparatively long and are therefore adapted for fast open ing to effect positive diaphragm operation of the cut-oil valve for vacuum flow for operation of the power cylinder. with the auxiliary valve arrangement shown, the vacuum supply ports are opened just before the valve reaches a new selector setting and then the vacuum effect will be quickly transmitted by the ports to the diaphragmfor opening of the cut-off valve. While the auxiliary valve is moving towards. new index setting, the atmosphere ports, which are of large area, permit quick venting of the diaphragm chamber for quick closure of the cut-off valve which then remains closed until the vacuum ports are exposed by the auxiliary valve during the final setting movement thereof. This will prevent operation of the power piston except when the index position of the auxiliary valve has been reached and the operator desires the shift to occur. The cut-oft valve 12 is thus under direct control of the operator and functions to shut out the main vacuum supply to the power cylinder until operation of the power cylinder is desired.

Either pre-selection or post selection may be used. When 'pre-selecting, the auxiliary valve I24 is set by operation of the setting lever M, and as the cut-off valve is then opened, depression of the clutch pedal will open the valve V for the ap, plication of vacuum to the power cylinder for neutralization of the gearing and shift to the selected speed.

When post selecting, the clutch lever is depressed for opening of the valve V, and as the cut-oi! valve is already open due to vacuum in the diaphragm chamber by way of the auxiliary valve, the power cylinder will function for shift to the indexed speed. If the auxiliary valve is in neutral, there will be no gear shifting, but if the auxiliary valve is in any speed index position,

shift will be made by the power cylinder for that speed. Selection from one speed to another may be made while the main valve V is held open, and then while passing from one speed selection to another, the diaphragm chamber will be vented to atmosphere by the auxiliary valve and the cutoff valve will be closed and will not open until the setting for the desired speed has been fully completed.

- 4| for the valve Y Referring to Figure 1, the setting of the-abutment 2 on the arm 48 operated by depression of the clutch lever C is such that the operating arm will not be actuated until the clutch pedal has been depressed a distance be- 'yond its movement for complete clutch disenvgagement. It will thereforebe impossible to shift gears until the clutch is fully disengaged,

It will also be noted that due to the rectangular valve port 51 and the rectangular ports 58 and I8, the valve has a fast straight line opening for full application of vacuum to the vacuum supcylinder. This is important with the arrangement shown where the auxiliary valve is directly connected with the vacuum supply source independently of the main valve V. Referring to Figures 5 and 6, a disk I88 is interposed between the vacuum pipe I38 and theport [8| of the auxiliary valve, this disk being provided with a metering orificel88 for retarding the application of vacuum to the diaphragm chamber 8! so as to delay opening of the cut-oil 'valve sufficiently to permit setting of the gear selection means and the auxiliary valve at a normal rate to the index position for the desired speed, and so that vacuvalve V is open, until the driver selects another speed or neutral. The reason for this is that when the reversing valve 85 has been shifted by the cylinder piston at the end of its neutralizing stroke to reverse the vacuum flow for return of the piston to shift, the reversing valve will remain in this position and the power cylinder will remain at shift until the reversing valve is restored to its normal position, it being remembered that after setting of the reversing valve by the power cylinder piston, the valve will be held in such position by the shifter bar I I l which is held in its outer position by engagement of the detent ball 8 in the channel I IS. The reversing valve will not be restored to normal position until the another speed or for neutral, such selection first 4o Figure '9 shows a circuit arrangement .for indicating various conditions for assuring proper manipulation of the piston.

A switch comprising a switch blade I48 is mounted for movement by the power cylinder piston and for cooperation with a contact III which is connectedwith ground. A suitable abutment III maybe provided for movement with the piston rod 28,- which abutment engages the switch blade Ill to disconnect it from the contact Ill to move the switch blade into engagement with the contact. The switch blade isconnected by conductor I with the contact Ill of a switch I which maybe the ignition switch whose blade is connected through a battery I with ground, the ignition circuit I48 extending from the switch contact I". The conductor- I includes a signal device, which may be a lamp I 4!.

For operation of-the power cylinder, the operator first depresses the clutch pedal 0 to effect complete disengagement of the clutch and then .when the piston is at'the inner end of its stroke after a complete shift cycle, a spring I48 tending to open the valve V for vacuum supply to the power cylinder. As soon'as the power piston starts to move outwardly, the abutment I42 will bereleased from the switch blade I40 which will then engage the contact I for closure of the circuit which includes the signal lamp I49, it being understood that the ignition switch I46 is closed before the system is operated. So long as the lamp I49 is lit, the operator knows that the power cylinder piston has not yet returned to its innermost position for full completion of the shift stroke and he does not therefore release the pedal C for clutch engagement. As soon as the'piston has completed its full inward travel, the switch blade I40 will be disconnected from the contact .blade I5I the rod has an abutment I which, I

when the clutch is engaged, holds the switch blade inengagement with its contact I52, I55 indicating the spring which tends to move the clutch lever to clutch engaging position. When the clutch lever is depressed for clutch disengagement, the rod I53 is raised and the switch blade will be released from its contact I 52 by the spring I51 and held against a stopll58.

When the operator closes the ignition switch I46 for operation of the vehicle, and-the power piston is at the end of a shift stroke, the switch blade I40 will be disconnected from the contact HI and there will be no current fiow to either of the signaling devices I49 and I50 and the operator then knows that it will be safe to de-.

press the clutch pedal for opening of the valve V for supply of vacuum to the power cylinder. However, should the power piston not be fully in and the gear shift last made was incomplete, the switch spring I40 and contact I4I will be in engagement and the lamp I49 will be lit and the buzzer or other audible signal device I50 will sound, thus warning the operator. As explained before, abutting gears or other conditions may have prevented the power piston from fully completing the shift. Under these conditions the operator will depress the clutch pedal again to open the valve V so that the power cylinder may complete, the shift into gear, the direct connection of the auxiliary valve with the vacuum source causing the vacuum in the diaphragm chamber ill to be maintained and the cut-off valve held opened for supply of vacuum through the reversing valve 85 to the inner end of the cylinder for completion of the shift stroke.

If, after the ignition switch is closed, the signals show the power cylinder in proper condition, he will depress the clutch pedal for unclutching, and opening of the valve V, and as soon as the power cylinder operates, the signal lamp I49 will light to indicate that the power cylinder has started operating. Upon depression of the clutch pedal, the rod I52 will be raised to release the switch blade I5I and to open the circuit to the audible signal I50, and should the operator attempt to engage the clutch before the power cylinder cycle has been fully completed, the switch will be closed by the downward movement of the rod I53 and the signal I50 will sound to warn the operator and he will then depress the clutch pedal for reopening of the valve V and completion of the power cylinder cycle.

We have thus produced a comparatively simple yet very eflicient control system for the transmission gearing in automotive vehicles. By means of the auxiliary valve operating'in synchronism with the setting. of the selection means at the transmission, the operator has at all times full control of the. cut-oil valve which in turn controls the supply of vacuum to the power cylinder and in conjunction with the power cylinder piston controls the reversing valve. By means of the reversing valve and its snap operation by the power cylinder piston movement, the power cylinder shift operation automatically substantially immediately follows the gear synchronization operation of the power cylinder. By the operator's control of the application of vacuum or atmosphere to the diaphragm structure which operates the cut-oil valve, engagement of the clutch cannot result until the power cylinder has fully completed its shift stroke for complete shifting of the gears to a selected speed. Should the power cylinder at any time fail to fully complete a shift, proper operating conditions can be quickly restored without strain or injury to any of the operating elements.

We have shown a practical and eflicient embodiment of the various features of our invention but we do not desire to be limited to the exact construction, arrangement and operation shown and described as changes and modifications may be made without departing from the vice for controlling the opening and closing of.

said cut-off valve, an auxiliary valve interposed directly between said vacuum source and said vacuum operable device, manually operable setting means for said selection means, means whereby said auxiliary valve may be manually set in synchronism with the setting means for the selection means for causing the opening of said cut-01f valve by said vacuum operated device when the selection means is set ready for operation of the shifting means and said cut-oil valve is closed during passage of the selection means from one setting to another, and a main valve between said source and said cut-off valve for controlling the application of vacuum through the cut-oil valve when openfor operation of the power cylinder.

2. An automotive vehicle transmission control system comprising gear selection means and gear shifting means, a power cylinder for operating the shifting means, a vacuum source, a cut-off valve for controlling the application of vacuum to the power cylinder, a vacuum operated device for con,- trolling the opening and closing of said cut-oil valve, an auxiliary valve interposed directly between said vacuum source and said vacuum operable device, manually operable setting means for said selection means, means whereby said selector valve may be manually set in synchronism with the setting means for the selection means for causing the opening of said cut-oil valve by said I 2,227,658 vacuum operated device when the selection means is set ready for operation of the shifting means and said relay valve is closed during e of the selection means from one setting to another,

a main valve between said source and said cut-oi! valve for controlling the application of vacuum through the cut-off valve when open for operation of the power cylinder, and a reversing valve be- I tween said cut-ofi valve and the power cylinder and operable by the movements of thepower cylinder piston and said cut-oi! valve to direct application of vacuum to the power cylinder for operation thereof to first neutralize the trn gearing and then to eifect shift into gear of the gearing selected by the selection means.

a 3. An automotive vehicle transmission control system comprising gear selection means and gear shitting means, a power cylinder for operating the shifting means, a source of vacuum, a main vacuum supply line, a main valve operable by the clutch lever oi the vehicle for connecting said main supply line with the vacuum source, a cutoll valve between the power cylinder and said main valve, a vacuum responsive device for controlling the opening and closing of said cut-off valve, an auxiliary valve controlling the connec--.

tion of vacuum to saidvacuum operative device directly from the vacuum source; manually operable setting means for said selection means, said settingmeans and auxiliary valve being connected for synchronous operation and said auxiliary valve being operable to cause said device to operate for means has been set ready for shifting into the selected gear by the'power cylinder and to cause operation or salddevice for closure of said cut-of! valve while said selection means is moving from one setting to another.

4. An automotive vehicle on control system comprising gear selection means and gear shifting means for the vehicle. gear mg, a power cylinder ror'actmting the-shitting means, amain vacuumsupply line, amain'valve source, a cut-off valve for controlling the connection of said supply. line with the p wer cylin- -for connecting saidsupplyline with a vacuum der, a vacuum operable device for controlling the opening and closing of said cut-oil. valve, 9. sup' ply line extending between said -vacuum source and said vacuum operative device and an auxiliary valve included in said supply line, said auxiliary valve being operable in with the selection means, and means for retardingthe how of vacuum to said vacuum operative device whereby when said main valve is opened while selection is being made, the selection means and auxiliary valve may be set from one index position to another without the vacuum. operated device being operated quickly enough for opening of the cut-oi! valve to start operation of the power cylinder between selection settings.

' 5. An automotive vehicle transmission control system comprising gear selectionmeans and gear shifting means for the vehicle on gearing, a power cylinder for actuating the shifting means, a main vacuum supply line, a main valve operable by the clutch pedal of the vehicle for controlling the connection or said main line with a vacuum source,-a cut-of! valve for controlling the connection of said main line with the power,

cylinder, a vacuum control device for controlling the opening andclosing of said cut-oil? valve, a

vacuum supply line for said vacuum control device and an auxiliary valve included in said line ineans whereby said auxiliaryvalve is operable iii syn-v chronism with the selection means to control the operation of said vacuum operable device for closing and opening of the cut-off valve, and means for restricting the how thr u h said auxiliary valve line wherebyduring post selection said outoii valve will remsin'closed until the selection setting for the desired speed hasbeen completed. Downer. HARRY L. CHISHOLH, JR. AI.|BERTE.WII BON. 1 

